Incoming call drops after 900 seconds

All the incoming calls we get over our sip trunk with drop after 900 seconds. I think this has something to do with session timers, but I don’t know what.

Ultimately the call drops with " Got SIP response 420 “Bad Extension” back from" after 900 seconds. More precisely if I look at packets, I see

A SIP invite from voipvoip with session-expires 1800, supported timer

Then all goes well for 900 seconds, after which my asterisk sends back and INVITE with Require timer and voipvoip answers with status 420, and unsupported timer.

Why is my asterisk sending back this invite after 900 seconds and requiring timer. Aill I see in sip show settings is

Session Timers: Accept
Session Refresher: uas
Session Expires: 1800 secs
Session Min-SE: 90 secs

There were problems in this area, addressed on You don’t seem to have specified a version. Make sure you have a current version. In the end, you may have to disable session timer support, if the far end is requesting them but can’t cope when it gets them.

I’m running

How do I disable session timer support? It’s already at “Session Timers: Accept”. If I set it to “reject” isn’t that going to cause trouble? … &history=1 … 4&type=bug

Seems to me that anything that isn’t happy with the refuse option will have a fundamental compatibility problem if it can’t actually cope with session timers.